Remnant Liver Volume to Body Weight Ratio ≥ 0.5%: A New Cut-Off to Estimate Postoperative Risks after Extended Resection in Noncirrhotic Liver

BackgroundBefore extended hepatectomy of five or more segments, the remnant liver volume (RLV) is usually calculated as a ratio of RLV to total liver volume (RLV-TLV) and must be > 20% to 25%. This method can lead to compare parts of normal liver parenchyma to others compromised by biliary or vascular obstruction or by portal vein embolization. Extrapolating from living-donor liver transplantation, we hypothesized that RLV to body weight ratio (RLV-BWR) could accurately assess the functional limit of hepatectomy.Study designFrom September 2000 to December 2004, volumetric measurements of RLV using computed tomography were obtained before right-extended hepatectomy in 31 patients. RLV-BWR of 0.5% as a critical point for patient course was compared with stratification by RLV-TLV (≤ 25% or > 25% and ≤ 20% or > 20%).ResultsThree-month morbidity and mortality were not significantly different between groups RLV-TLV ≤ and > 25% and between groups RLV-TLV ≤ and > 20%, but increased significantly in group RLV-BWR ≤ 0.5% compared with group RLV-BWR > 0.5% (p = 0.038 and p = 0.019, respectively) with an non-significant increase in death from liver failure (p = 0.077).ConclusionsRLV-BWR was more specific than RLV-TLV in predicting postoperative course after extended hepatectomy. Patients with an anticipated RLV ≤ 0.5% of body weight are at considerable risk for hepatic dysfunction and postoperative mortality.